Power feed motor

[pollaccia]

I have a 24VDC motor, with 30 inch pounds of torque. It is a 500ma motor, do you think this would motor would work as a power feed motor? Thanks in advance Paul

 

[cheepo45]

It depends on what you are going to power feed. You will need to gear it down quite a bit, which will increase the torque. Give us some more information and we will be glad to help you out.
I have a gearmotor from an old copier that I use for the power feed on my Mill-Drill. It works great with an old battery charger for power.
cheepo45

 

[pollaccia]

The specs on the gearhead motor is 500ma, 24 VDC, and 30 inch pound of torque, and 300rpm. I will be hooking this to a DPDT switch, and a PWM circuit. I don't know if this motor will have enough torque to turn the screw on the x axis. This will be going on a Harbor freight x2 mini mill. Thanks Paul

 

[cheepo45]

You can use a torque wrench to get an idea of how much it will take to turn the leadscrew. Remember it will take more when it is actually cutting.
You may want to rig something up temporarily to make sure your motor will work before you spend a lot of time adapting it.
cheepo45

 

[lemelman]

The power feed motor on my Centec 2B is 0.5hp, or 0.375kw, your 24v motor is only 0.012kw.
I don't think 30 inch/pounds is anything like enough, unless you intend to move the table very slowly indeed.

 

[Tin Falcon]

most steppers are rates in in/oz so converting in/lbs to in /oz you end up with 480 in oz.
that will move a mill table how heavy is the table this will determine how fast you can move it.
Tin

 

[lemelman]

It's not just the weight of the table you have to consider, you also have to factor in the force required to push the cutter into the work, and this is dependent on the depth and rate of cutting. It's certainly more than is required to simply move the table.

 

[Tin Falcon]

I think you need to read the gecko site on how to size a motor. yes there are considerations like friction . but this info is based on information from a guy that provides automation equipment for lots of machines . I am not making it up.

(Heaviest object * IPM) / 531 = Watts required

I do have to agree a 12 watt motor will not move a mill table very fast but if you know the weight of the table we can plug the numbers in and find max Inches per minute of feed.
Tin

 

[schilpr]

Have heard several people getting good results with motors from battery powered drills, most of those have a gearbox and clutch and run on 12v to 18v, with plenty of torque and speed. They are also cheap, because after the battery goes out buying a new drill is often cheaper then replacing the battery.

 

[Johnvankoeveringe]

I have used a automotive window motor on my mill drill unit for about 10 years with good success.
I designed a very simple clutch and a reverse switch .
I build a small power supply with an 15 and 30Vdc outputs 30V is only used to return the table (no load)
The output is pulsated and the pulse width is controled with a rotory knob.
so the motor always runs at the selected voltage (15 or 30Volts) but the width of the pulses controls the speed.
John VK.

 

[tornitore45]

Lemme do a quick guess... the manual feed wheel may have a 2" radius at the crank.
A 30 inch-pound would be equivalent to 15 pounds applied to the wheel handle.

If I had to apply a constant 15 pound force with my arm during manual machining I would be sore in 30 minutes.

300 RPM means 30"/minute that is a good clip for cutting, a 2:1 reduction may still give a slow but acceptable traverse speed.

On a small machine (X2) friction is much higher than cutting forces, I would just rig up a temporary coupling to the crank hub and see how it goes.

By the way, the weight of the table is not the main factor, friction is.
A man can push a 4000 pound car on level; after acceleration just holding it running is working agains friction only, mass per se just keep on running.